基码

Firstly, it's proved that the base of free monoid is unique, and that the equation of a base, a generating set and a irreducible generating set in the semigroup with length; Secondly, it's given the relation of a primitive word and a word of indecomposable--Let and is indecomposable, then is primitive ;And by using the length's method and chart,some properties of primitive word have been proved and the solutions of the equation , are discussed; Lastly, on the base of some proposition in Free monoids and Languages ,the proofs of some properties are improved by instruction. For example: Let be a primitive word over X, where .Then is a code. And let then if and only if {} is a code.

首先，讨论了含幺半群中基的基本性质及基与最小生成元集的联系，并给出了含幺半群中基、生成元集、不可约生成元集三者之间的关系；证明了在有唯一长度的半群S中，不可约生成元集、基、最小生成元集三者之间的等价关系；其次，讨论了字的组合与分解性，得出了字的本原性与不可分解性之间的关系---若为不可分解的，则一定是本原的，反之，不一定真；并运用图示法证明了字的可补性理论，讨论了方程，的可解性；在此基础上，用归纳法进一步证明了本原字与码的有关命题--若是X上的一个本原字，其中，则是一个码；若则当且仅当{}是一个码。

In this paper,the influence of the Doppler shift on the performance of the PN code acquisition circuit is analyzed,and the method of orthogonally relative elimination is proposed to eliminate the Doppler shift.

文章在分析多普勒频移对PN码捕获性能影响的基础上，采用基带正交对消法去消除多普勒频移，消除了多普勒频移对PN码捕获电路的影响，解决了低信噪比情况下在基带上消除多普勒频移的难题。

In this algorithm, the multiplier and multiplicand are represented with standard basis and there is not transform from basis to basis. In the end, the encoding process of RS (255,223) code is simulated.

该算法中乘数与被乘数都采用标准基来表示，而不需基与基的转换；最后对RS(255，223)码编码器的设计过程进行了计算机模拟。

In chapter five, the base band signal process of CDMA base station simulator system is introduced, including channel coding and decoding, interleave and disinterleave, PN sequence generator, orthogonal spread spectrum and quadrature Spreading, scrambling code, power control, digital forming filter, the capture and track of PN code, dispreading and demodulation, etc. Some FPGA design graphic and waveform simulation of base band transmitter module is given and realization algorithm of base band receiver is discussed in detail.

第五章介绍了CDMA基站仿真系统的基带信号处理过程，包括信道编译码、交织与去交织、PN码发生器、正交扩频与四相扩频、扰码、功率控制、数字成形滤波器、PN码的捕获与跟踪、解扩与解调等，并给出了基带发射机模块的部分FPGA设计原理图和波形仿真，详细论述了基带接收机模块的实现算法。

This paper mainly introduces the baseband transmission and the waveband transmission of digital communication system.

介绍了数字通信系统中信号的基带传输和频带传输；分别论述了基带传输系统和频带传输系统模型，说明了基带信号无码间干扰传输条件及频带数字调制的工作原理。

The gene (named as SenAChRβ1) was 2231 bp, with an open reading frame of 1575 bp encoding a predicted nACh receptor protein of 524 amino acids with a molecular weight of 60 kDa.

该基因命名为SenAChRβ1，其长度为2231个碱基，含有一个1575个碱基的开放读码框，开放读码框编码524个氨基酸残基，预测的分子量为60 kDa。

With many genomes, coden bias provides a useful means of assigning a degree of certainty to a possible gene identification.

至于许多基因组，基码偏差为可能基因鉴定分配确定度提供有用的方法。

But if their new bacterium is at least viable, it will have 43 codons that can be re-assigned to other tasks.

不过，只要他们的新品细菌可以存活，这个细菌将有额外的43个基码可以被分配去做其他任务。

But, with more codons than amino acids, many amino acids have more than one codon to describe them.

由于基码的数量比氨基酸多，许多氨基酸有超过一个基码来表述它们。

The letters are grouped into three-letter "words" known as codons, meaning that there are 64 of them.

这些字母可三个一组地组成&单词&，称为基码，这样的基码总共有64个。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。